Method of converting the energy taken from high-tension continuous-current-surrly mains into alternating current



METHOD OF oeuvsa'rms THE} ENERGY TAKEN FROM HIGH TENSION June 22 1926.

F. BERGTER CONTINUOUS CURRENT SUPPLY MAIHS INTO ALTERNATING CURRENT3.921 2 Sheets-Sheet 1 Filed Kay 7 Fig.1

Jun 22 1.925.

F BERGTER METHOD 01- CONVERTING THE ENERGY TAKEN FROM HIGH TENSIONCONTINUOUS CURRENT SURPLY MAINS INTO"ALTERNATING- CURRENT Filed May 71921 2 Sheets-Sheet 2 r Fig. 2

Patented June 2 2, 1 926;

Tumrso STATES PATENT OFFICE.

. mrrnon or 1, columns-s A neauon med May 2,1921, Serial not For theconversion into alternating cur- "rent of continuous current'energy.-transmit ted over long distance lines at a high tensionit ispossible to employ highly evacw ated discharge vesselswith incandescentI cathodes in conjunction with a transformer.

Upon the grids of these discharge vessels fluctuating potentials areimpressed in such a way that the energy taken by the discharge vesselfrom the continuous current mains isr fed to the transformer inthe'iormof pulsatingcontinuousicurrent and taken from thetransformer as-analternatin current.

Inarrangements of thiskind I rg'e losses 'of energy occur either in'thedischarge vessel or in'the. transformer; for if the continuouscurrentlis taken from the supply main the-form of sinusoidalfluctuations:

which, as is-well known, givesthe best efii 'ciency of the-transformer,thefdischarge vessel itself.- will fc'o some at least one half of theenergy supp ied' from the mains.

. This loss'in the discharge vessel may he re'ducedto a very smallamount if the sinu- 'soidalfcirin 'of discharge is departed from and itsshape is nlade such that eithe r the current or the voltagein thedischarge ves- 'sel is verygnearly zero during 'the major part of eachperiod. Y This measureis known 'in'the art of 'wireless' telegraphy butwould "fail in the case under discussion, because the altered form ofcurve entails very great losses in the transformer.

' Byi thepresent' invention it is possible toreduc'ethe-loss of energy.both in the discharge vessels and in the transformer to an-extrcmly-sinallamount and thus to. obtain :acco

ciency of more than 90%. This is plished by producing by a number, oficebergs-vessels a number of collateral c'urrents'o f a wave .form thatgives small losses iu'the vessels, and in so uniting or 5 superimposingthe collateral currents in a transformer that a sinusoidal currentreults-which is conducive of ahigh eflicienc v {in the-trans'former.-:

-The invention is illustrated in the drawing in WhiGh'Fi'g; 1 shows acircuit arrangement which may housed in cases in which threedischargeveesels are employed, and i Fig, 2'showe: the wave forms of thecollateral currents and of the sinusoidal currnmpmcnfnamrnn, orn'nnmiwcnnmorrsnnnno, GERMANY, nsszcnon; BY:

- amen: ASSIGNMENTS, T0 GENERAL ELECTRIC COMPANY,

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convmmrive; HQE'ENEQRGY craxnurnom men-Tension cons-muons- Y MAINS INTOamnnua'rme connnur.

467,878 and in Sweden January 22 192i.

upon which a fourth coil T is placed from which the sinusoidalalternating current is taken that is sup lied to the'alternatingcurrentmains W; geparate sources of electric potential 8,, S and S deliventhedifferent grid potentials whose periodic variations,

in addition to the inductive reactionof the transformer, are the factorsthat determine the wave form of the currents and potentials deliveredfrom the anodes of the discharge Ke'sse'ls' Any source or sources ofvariable F. of current such as an A. C. generator or generators of asimple type can he used for the sources S S S (adjusting the magnetic"poles of the generators for example, to effect thedesired phaserelationship).

Examples of preferred forms of current and potential curves, in caseswhere three discharge vessels are used as described, are shown in Fig.2a-(i. In all these figures E is the voltage, J the current and W theenergy. Fig. 2a applies to-tlie first dis charge vessel R,. It will beseen that at the moments in which the current values are high thepotential is almost at zero, whilst at times when the potential is highthe current values are insignificant. Hence the product of these twovalues. 1. e. the loss of energy'in the vessels, is very small duringthe greater part of the period, as Will be seen by inspection of thecurve W. The preferred wave forms given by the second and thirdevacuated tubes or discharge ves I Figl lll ithc superimposed collateralcurrent waves and the curve resulting from the sum of the threecollateral currents is re re-I sented. The latter curv is completelys1nusels are shown in Figures 2?) and 2c.

soidul, i. e., its shape is. such as to give rise v to the smallestpossible loss inthe transformer.

15 all times.

I claim:

The method of converting' current from a lowest value almost equal to aD. C. source into alternating current without serious loss of energywhich comprises supplying energy from said source through each of themultiple primary coils of an A. C. transformer and causing the-energyfrom each of said coils to flow through a highly evacuated dischargevessel or tube to the other pole of the D: C.. system, and varying thegrid potential .of each-tube in relation to the impedance of- -the primary .coil in that branch so as to produce in a single secondary coilinductively coupled toall-0f the priinary coils a resultant sinusoidalcurrent. In testimony whereof I atfix my signa ture.

" FR. BERGTER

